| 摘要 |
An optical device 35, which may be used as a sending unit for a quantum communication system, comprising an optical component 30, e.g. gain-switched laser (24 fig.2(a)), configured to produce optical amplification, a component 20 configured to intermittently supply coherent light 21 to the optical component 30, and a controller 141 configured to apply a time varying signal to the optical component 30 such that a plurality of light pulses 26 are emitted during each period of time that the coherent light 21 is received. The light pulses 26 emitted during each period have a fixed phase relation, e.g. the phase difference between any two consecutive intra-period pulses may be the same for all periods and/or the phase difference between inter-period pulses may be random. The optical device 35 may also comprise an encoder configured to encode information in the emission time of the light pulses 26 or in the phase difference between the light pulses 26. |
